Stiffening material



v Jan. '14, 1936; l ussg 2,2?,96

STIFFENINGUMATERIAL Filed Aug. 19 1953 High/(j Porous Dupes/l fPrecrplvafed Collolclal Malena! 8. Cellulose Esfer v More Col/aid d andMore Sch/em- Res/diam Colloidal Mafer/a/ 6. Cellulose Esfer ATTORNEYPatented Jan. 14, 1936 UNITED STATES PATENT OFFICE STIFFENING MATERIAL II Joseph Fausse, Melrose Highlands, Mass., 115- I signer to The CelasticCorporation, Wilmington, DeL, a corporation of Delaware ApplicationAugust 19, 1933, Serial No. 685,908

10 Claims. (01. 12-14 This invention relates to stiffening material andparticularly to an improved material of the general type disclosed in U.S. Patent 1,256,240, Lovell, February 12, 1918. Although not restrictedto such use, materialof thepresent type finds advantageous applicationas stiffening material for boots and shoes, such as fabric, patentleather, cut-out, or perforated boots and shoes, and therefore isdescribed with more particular reference to the boot and shoe industry.

Material of the Lovell type comprises a base fabric such as a wovenmaterial, for example cotton-cloth, or a structureless material, forexample felt or paper, with its interstices carry- 15 ing a precipitatedcolloidal material in a highly porous form termed powdered by Lovell,such as a cellulosic derivative, casein, albumin and various gums andresins. immersed in a solvent for the precipitated material, thereby toresolve the same into a coalescent flaccid condition, and when thematerial is in this condition the fabric is applied in the lastingoperations, shaped, and allowed to harden, by evaporation of solvent, inits shaped condition.

While material of the Lovell type is highly satisfactory in use, itsometimes gives rise to the difficulty that the colloidal matter becomesso soft and mushy when the stiffener is dippedinto the solvent, that thecolloidal matter can be forced through the upper of a shoe of fabric orsimilar material, during the lasting operations, thereby staining,disfiguring and ruining the upper; and similarly, the coating on apatent leather shoe upper will be affected and softened during thelasting operations so that the coating,

will be peeled from the leather, thereby damaging theupper; and, again,in lasting shoes having cut-outs or perforations in the upper, the

colloidal matter may be forced through the cutcuts or perforations.

I have now devised a stiffening material of the general Lovell typewhich in itself, and because of particular character of the stiffeningdeposit, overcomes the dilficulties mentioned, and

45. have also devised a method for the manufacture of such material.

In-the accompanying drawing, the figure is a highly conventionalexaggerated cross sectional view of stiffening material made inaccordance 50 with the present process and embodying the presentinvention.

One object of my invention is to provide a stiffening materialof thementioned and other desirable characteristics. A further object is to 5provide a method for the production of such In use, the fabricismaterial. To these ends, and also to improve generally on materialsand methods of the general character indicated, my invention consists inthe various matters hereinafter described and claimed.

These objects are accomplished by treating one side of the stiffenermaterial with a solvent for the colloid, and drying the material, beforeit is dipped for use as a stiffener. Proceeding in this way a firm fihnis created on the treated side. 10

This film is relatively continuous and the colloidal material therein,firmer, harder, more colloided and-more solvent-resistant as compared tothe untreated colloidal precipitated material with which the fabric as awhole is filled. As a 5 result, when the stiffener is dipped in solventfor the purpose of preparing it for use in the lasting operation, whilethe untreated precipitated colloidal material is rendered flaccid andcoalescent in accordance with Lovells general procedure, 20 the fihnformed by the described treatment, although it is softened sufflcientlyand rendered sufficiently flexible, to permit the proper use for shapingof the stiffener in lasting, doe s not become so soft and mushy that itwill, in the last- 5 ing operations, penetrate the fabric, cut-outs orl,

perforations in the shoe upper, or give rise to the troubles with patentleather, above mentioned.

It will be understood, of course, that the treated side of the fabric isthat side which, 30 ordinarily is, in the lasting, used as the top sideand placed immediately next to the upper, the untreated side of thematerial being ordinarily the inner side in use. Further in respect tothe. use of the material with patent leather, the ma- 35 terial will nothold such an excess of solvent that the coating of a patent leatherupper will be affected and peel and rub off during the lastingoperations. I

In greater detail, the invention maybe prac- 40 ticed, and an improvedstiffener for boots and shoes, made as follows. Taking a finished sheetof the colloid-treated shoe stiffener material, containing theprecipitated colloidal material in general accordance with Lovell, Iapply to one side, by any suitable means, a solvent for treating thesame. There are several ways of treating the one side; For example, asolvent for thecolloidal matter may be painted on with a brush, mop,or'cloth, or may be applied to the one side by passing the stiffenermaterial between two rolls, one of which passes through a bath ofsolvent whereby some of the solvent' is carried on the surface of theroll and transferred to the surface of the stiffener material at thepoint of contact. Or the same effect may be obtained with an endlessbelt of fabric or other material suspended from one of the rolls, withthe other end passing through a bath of solvent. Again the solvent maybe applied by spraying thesame on the one side of the material.

The amount of solvent to be applied and the extent to which the materialis treated there- I with will, of course, depend upon the amount andthickness of the deposit in and on the particular treated fabric beingprocessed, the size of the beading roll, the height of the solvent inthe tank, the speed of the fabric, and the particular type of stiffenermaterial, etc., as will be understood by those skilled in the art, .whowillvary the various factors to suit the particular conditions, havingin mind the particular feature of the invention; that is, that colloidalmaterial on but one face of the stiffener material is to be treated, andcare taken that the alteration in the colloidal material to convert itinto a firm and relatively solvent-resistant layer, is not to be allowedto proceed to the extent of penetrating entirely through the stifienermaterial. The material, having been thus treated is now dried of solventin any suitable manner, e. g. air dried, thus giving the desired firmcontinuous deposit on the one side.

Blanks of suitable shape may now be cut from the treatedmaterial. In usethese are dipped into a suitable solvent, e. g. diacetone alcohol andethyl alcohol which will render the blank soft enough to conform to thedesired shape. A treatment sufficient to render thedeposit on theuntreated side of the stiffener material, and therein, sufiicientlycoalescent and flaccid to be utilized in accordance with the Lovellinvention will not render the deposit on the treated side soft and mushyor cause it to hold such an excess of solvent that it can be forcedthrough fabric or perforated shoe uppers, or cause patent leather shoeuppers to peel during the lasting operations. softness and flexibilityto the treated side.

While the stiifener is in this condition it is cable may be, as aboveindicated of many general types. Whenpf cellulosic derivative, it may beof cellulose ester, e. g. cellulose nitrate or cellulose acetate, orcellulose ether, e. g. ethyl cellulose or benzyl cellulose. The solventfor treatment in accordance with the present in-' vention will, as willbe understood by those skilled in the art, be a solvent compatible withthe particular colloidal substance in the stiffen- .ing material, e. g.acetone for cellulose esters and ethers and certain gums, e. g. gumcopal. Generally speaking, for Lovell material having a fabric e. g.flannel for a base and carrying about six ounces of precipitatedcellulose nitrate per square yard, I find that ten seconds treatmentwith twenty percent ethyl acetate is adequate for the purposes of theinvention in the treatment of the stiffening material.

While boots and shoes have been more particularly referred to, it willbe understood that stiifeners of the present type may be used in anyarticle of footwear where their use recommends itself, and furthermore,may be used at It will, however, impart sufilcient its treatment inaccordance with the present invention may be carried on as a singlecontinuous process.

It will be particularly noted that in the present stiffening materialthe protective advantages are attained by the stiffening deposit itself.Thus, the entire colloid content is capable of being softened by asingle solvent. That is, the protective harder and firmer portion of thecolloid is softenable sufficiently for lasting purposes by the solventused for treating the stiffener, and particularly the unalteredprecipitated portion, with the result that the protective portionfunctions in the stiffener as does the precipitated portion so far asbeing a stiffening factor is concerned. The entire colloid content ispreferably water-insoluble.

I claim:

1. Method of treating a stiffening material for shoes and the like, ofthe type comprising fabric carrying a cellulosic derivative precipitatedin the interstices thereof which method comprises applying a solvent tosaid material to dissolve only part of the cellulosic derivative withoutremoving it from said fabric, drying the material to convert thedissolved cellulosic derivative into a colloided solvent resistant formwhile leaving the remaining cellulosic derivative in its originalprecipitated form, and thereafter treating said material with acellulosic derivative solvent to soften it, shaping it, and allowing itto dry in the desired final form.

2. Method of treating stiffening material for shoes and the like, of thetype comprising fabric carrying cellulose nitrate precipitated in theinterstices thereof which method comprises applying a solvent to saidmaterial to dissolve only part of the cellulose nitrate without removingit from said fabric, drying the material to convert the dissolvedcellulose nitrate into a colloided solvent resistant form while leavingthe remaining cellulose nitrate in its original precipitated form, andthereafter treating said material with a cellulose nitrate solvent tosoften it, shaping it,

and allowing it to dry in the desired final form.

side of the material without removing it from said fabric, drying thematerial to convert the dissolved cellulosic derivative into a colloidalsolvent resistant form while leaving the cel1u- -losic derivative in itsoriginal precipitated form on the other side, and thereafter treatingsaid material with a cellulosic derivative solvent to soften it, shapingit, and allowing it to dry in the desired final form.

4. Method of treating stiffening material for shoes and the like, of thetype comprising fabric carrying cellulose nitrate precipitated in theinterstices thereof which method comprises applying to one side only ofsaid material a solvent to dissolve the cellulose nitrate on said sideof the material without removing it from the material, drying saidmaterial to convert the dissolved cellulose nitrate into a colloidedsolvent resistant form while leaving the cellulose nitrate in itsoriginal" precipitated form on the other side, 76

to be treated with a cellulosic derivative solvent to soften same, andthen shaped and dried'in the desired final form. 1

6. A stiffening blank comprising a fabric having cellulose nitratedisposed in the interstices thereof, part of said cellulose nitratebeing in precipitated form readily subject to the action of solvent andpart being in a colloided solvent resistant form, said blank beingadapted to be treated with a cellulose nitrate solvent to soften same,and then shaped and dried in the desired final form.

7. A stiffening blank comprising a fabric having a cellulosic derivativein precipitated form in the interstices thereof on one side and havingsaid cellulosic derivative in a colloided solvent resistant form on theother side, said blank being adapted to be treated with a cellulosicderivative solvent to soften same, and then shaped and dried in thedesired final form.

8. A stiffening blank comprising a fabric havingcellulose nitrate inprecipitated form in the interstices thereof on one side and havingcellulose nitrate in a colloided solvent resistant form on the otherside, said blank .being adapted to be treated with a cellulose nitratesolvent to soften same, and then shaped and dried in the desired finalform.

9. A stiffening blank comprising a'fabric having cellulose acetate inprecipitated form in the interstices thereof on one side and havingcellulose acetate in a colloided solvent resistant form on the otherside, said blank being adapted to be treated with a cellulose acetatesolvent to soften same, and then shaped and dried in the desired finalform.

10. A stiffening blank comprising a fabric having a cellulose ether inprecipitated form in the interstices thereof on one side and having saidcellulose ether in a colloided solvent resistant form on the other side,said blankbeing adapted. to be treated with a cellul ose ether solventto soften same, and then shaped and dried in the desired final form.

JOSEPH FAUSSE.

